1. Field of the Invention.
The present invention relates to a method for detecting the presence of tumor cells in the body by detecting the presence of human Thomsen-Friedenreich antigen.
2. Information Disclosure Statement
The immunodominant group of the Thomsen-Friedenreich (TF) erythrocyte antigen is characterized as [D-.beta.-Gal (1-3)-.alpha.-GalNAc]. The TF hapten is expressed in cryptic form in normal human red blood cells where it is a precursor structure of the M and N blood group antigens, and in normal epithelial cells. The TF hapten is revealed by removal of the terminal sialic acid residues by neuraminidase treatment.
Springer and coworkers have reported that about 90% of the human carcinomas express TF hapten in non-cryptic form.sup.2. The TF antigen is capable of eliciting both humoral and cell-mediated immunity in mice.sup.3-6 and in cancer patients.sup.7,8, and in animal models it can stimulate effective anti-cancer immunity. In breast cancer patients increased expression of the TF antigen has been correlated with tumor progression and metastatic spread.sup.9. Studies on the expression of this antigen in bladder carcinomas suggest that it may serve as a prognostic marker.sup.10-13. Immunohistochemical studies on normal, premalignant, and malignant colonic tissues have shown that the expression of TF antigen is associated with malignant and premalignant changes in colonic mucosa.sup.14-16. Further, TF antigen has also been implicated in organotropic metastasis of tumor cells.sup.17. For these reasons, an assay for tumor-associated TF antigens would be of value to the clinician.
The cryptic TF antigen in red blood cells is known to be glycophorin, and has been well characterized. A murine cancer-associated TF antigen, epiglycanin, has also been subject to detailed chemical and biochemical investigations.sup.25,26. However, the molecular characteristics of the TF antigen expressed by human tumor cells has not yet been described.